Pulis admitted Robson-Kanu was a "bit-part player" at West Brom before he scored his thunderous winning goal in the 2-1 Premier League victory at Southampton on New Year's Eve.
Robson-Kanu's first top-flight goal in more than three years, on his first start for West Brom, handed the Baggies three points on the south coast, leaving Pulis with a selection dilemma.
West Brom host Hull at The Hawthorns on Monday, with manager Pulis facing a tough call on whether to start Robson-Kanu or Salomon Rondon up front.
"Well on Monday I've got a decision now, haven't I?" said Pulis of whether Robson-Kanu can now fight for regular action at West Brom.
"Hal's attitude round the club, his willingness to work and join in, even though he's only been basically a bit-part player, because of Salomon, has been fantastic.
"I can't speak more highly of his character.
"He's just so wholehearted
He gives you everything all the time.
"So we had no problems in starting him at Southampton - the difficult thing was leaving Salomon out, because he's been fantastic for us as well."
Shane Long headed Southampton into the lead at St Mary's on Saturday, only for Matt Phillips to slide home a rapid-fire equaliser.
West Brom upped the attacking ante after the break and gained almost immediate dividends, with Phillips playing in Robson-Kanu for the stunning winner.
The 27-year-old took one touch before unleashing an unstoppable piledriver that left Fraser Forster flailing and sealed West Brom's win.
Robson-Kanu hit seven Premier League goals with Reading in the 2012-13 season, only to drop down a division with the Royals.
The London-born forward helped Wales to the Euro 2016 semi-finals while a free agent with his club future in limbo
West Brom stepped in to secure his services in August, though, with Pulis continuing to be impressed by his drive.
Pulis admitted his side can ill afford the kind of slow start that hampered their Southampton clash when facing Hull on Monday.
West Brom's flight down to the south coast on Friday was grounded by fog, forcing Pulis and his squad to travel by a hastily arranged coach.
The former Stoke and Crystal Palace boss hopes those logistical delays can account for a sluggish start at St Mary's.
"I thought in the first half we were awful really, we sat there and never did anything, never threw a punch," said Pulis.
"Southampton when they scored, deservedly, were the better side.
"We scored a great goal before half-time and it really gave us a lift.
"And in the second half I thought we were the better team.
"Hal scoring early on released all the shackles from the players and in the end we could have won by more goals.
"In the first half I don't really know what the reason was.
"We had our flight cancelled on Friday
We were at the airport, the flight was cancelled and the bus had already travelled down.
"So we had to get another bus to come down and it took about four or five hours to get down.
"So whether that was in their legs or not I don't know.
"But the performance between the first and second half was chalk and cheese."
Source : PA
Source: PA